Standard therapy in the treatment of many illnesses is the administration of a pharmaceutically active ingredient in tablet dosage form, which often requires the patient to swallow the tablet intact. In order to improve the swallowability of a tablet, it is known in the art to coat the surface of the tablet with a polymeric film, which provides several benefits to the patient. First, it reduces the adhesion of the tablet to the inner surface of the mouth, thereby increasing the patient's ability to swallow the tablet. Second, it aids in masking the unpleasant taste for certain drugs. It also can protect components from atmospheric degradation and improve appearance.
Polymeric films typically used in such film coating include, for example, (1) vinyl polymers such as polyvinylpyrrolidone, polyvinyl alcohol and acetate, (2) cellulosics such as methyl and ethyl cellulose, hydroxyethyl cellulose, hydroxypropyl methylcellulose and hydroxypropylcellulose, (3) acrylates and methacrylates, (4) copolymers such as vinyl-maleic acid and styrene-maleic acid, and (5) natural gums and resins such as zein, gelatin, shellac and acacia. See Remington's Pharmaceutical Sciences, 15th Ed. Mack Publishers (1975) p. 1613.
While the film coating adds certain advantages to the tablet formulations, one disadvantage is that the film coating may reduce the onset of action of the drug by retarding disintegration of the tablet. In certain cases, this can retard the disintegration of the tablet within the first few minutes of contact with a liquid medium. This can affect the performance of certain medications such as antacids where a fast onset of action is desirable. There is thus a need for a film coating composition which exhibits enhanced disintegration characteristics in order to provide more rapid delivery of active and faster onset of action.
The use of disintegrating agents such as dried starch, sodium alginate, lactose, sodium bicarbonate, calcium carbonate, polyvinyl pyrrolidone, microcrystalline cellulose and the like in the tablet core or granulation mixture of a swallowable tablet formulation is known. For example, U.S. Pat. No. 4,965,072 discloses the use of a mixture of magnesium sulphate heptahydrate and sodium hexametaphosphate to prepare a granulating composition with an active ingredient, which, when formulated into a swallowable tablet, exhibits rapid disintegration or dispersion.
In recent years, several newer agents have been developed known as “super-disintegrants”. These newer substances are more effective at lower concentrations with greater disintegrating efficiency and mechanical strength. On contact with water the super-disintegrants swell, hydrate, change volume or form and produce a disruptive change in the tablet. Effective super-disintegrants provide improved compressibility, compatibility and have no negative impact on the mechanical strength of formulations containing high-dose drugs. However, the use of disintegrating agents and/or super-disintegrants in the tablet core in such a manner does not address the problem associated with the slow dissolution of the polymeric film in a film coated tablet.
U.S. Pat. No. 6,413,549 to R. P. Sheerer Corporation discloses a rapidly disintegrating, freeze-dried dosage form comprising coarse particles of active coated with a polymer or lipid material.
U.S. Pat. No. 7,125,562 to SmithKline Beecham Corporation discloses disintegrating methylcellulose tablets. The patent discloses that the tablets have a first phase and a second phase blended with the first phase and that each phase may contain a disintegrant and a polymer.
European Patent No. EP878189 B1 to Hercules Incorporated discloses the use of hydrophobically modified polysaccharides, including hydroxypropylcellulose, in personal care products.
U.S. Application No. 20050255054 to Philip et al. discloses a dissolvable tooth whitening strip that contains a dissolvable substance such as a freeze-dried hydrogel containing acemannan.
U.S. Application No. 20070077300 A1 to Wynn et al. discloses oral dosage forms that contain salivation inducing agents that may be in the core and/or the coating of the dosage form.
U.S. Application No. 20080292669 to SmithKline Beecham Corporation discloses foamed substrates for transmucosal and/or transdermal applications that comprise one or more polymers and one or more foaming agents, and that may comprise one or more plasticizers, hydrophobic barrier agents, tooth whitening agents, antioxidants, preservatives, super-disintegrants or absorbents, flavorants, deodorants, breath freshening agents, colorants, surfactants, film modifiers, cross-linking agents, antimicrobial agents, control release agents, other therapeutic agents, or any combinations thereof.
International Application No. WO2008079963 to Cambrex Charles City, Inc. discloses ionic complexes of anion-containing APIs that can be coated with a pharmaceutically acceptable coating.
U.S. Application No. 20090047330 A1 to Bangalore discloses water soluble polymer based edible films that are prepared using the formulation composition disclosed therein along with other ingredients including plasticizers, fillers, taste masking agents, disintegrants, and colorants.
U.S. Pat. No. 6,627,224 to Bristol-Myers Squibb Co. discloses a process for making a pharmaceutical composition that comprises entecavir, comprising forming a solution of entecavir and an adhesive in a solvent, depositing the solution on substrate particles, drying and mixing the coated substrate particles with other ingredients, including disintegrants.
U.S. Pat. No. 6,660,382 to Ethypharm discloses a process for preparing coated granules with masked taste and immediate release of active that comprises: dry-mixing the constituents of a powder comprising at least the active and a disintegrant; granulating the resultant powder in the presence of a binder to obtain granules; coating the granules formed by spraying a suspension comprising at least one coating agent and one disintegrant; and drying the resulting coated granules.
U.S. Pat. No. 5,807,580 to McNeil PPC, Inc. discloses pharmaceutical compositions comprising a film coated tablet exhibiting enhanced disintegration characteristics that comprises a hydrophilic film forming polymer and an alkaline agent such as an alkali metal, an alkali earth metal carbonate, or a bicarbonate such as sodium or potassium bicarbonate, wherein the alkaline agent reduces the disintegration time of the film coating by increasing the rate of removal of the film coating polymers.
There continues to be a need for pharmaceutical compositions and more particularly film coated tablet compositions having enhanced disintegration characteristics